1. Field of the Invention
The present invention relates to a copper alloy wire rod and a method for manufacturing the same.
2. Description of the Related Art
Heretofore, Cu—Zr based copper alloys have been known as copper alloy wire rods. For example, PTLs 1 and 2 propose copper alloys for wire rods, wherein the electrical conductivity and the tensile strength are improved by subjecting a copper alloy containing 0.01 to 0.50 percent by mass of Zr to wire drawing to a final wire diameter while a solution treatment is performed and, thereafter, performing a predetermined aging treatment. The strength of these copper alloy wire rods is enhanced by precipitating Cu3Zr into a Cu parent phase. Also, PTLs 3 and 4 propose copper alloys, wherein the strength and the electrical conductivity are improved by subjecting a copper alloy containing 0.005 to 0.5 percent by mass of Zr and 0.001 to 0.3 percent by mass of Co to a solution treatment while hot rolling is performed, followed by cold rolling, and subjecting the parent material after the cold rolling to a heat treatment. Meanwhile, NPL 1 proposes that a copper alloy containing 0.33 to 2.97 percent by mass of Zr is melt-refined, and precipitation hardening and Cu3Zr dispersion hardening are realized at the same time by combination of hot rolling, a solution treatment, and an aging treatment so as to enhance strength without impairing the electrical conductivity to a large extent.